The dough for this traditional Jewish cookie or pastry (it fits the bill as both) is rich and soft and must be made a day ahead and refrigerated before rolling out. We’ve filled these with apricot jam—but seedless raspberry, peach, strawberry and currant jellies are also wonderful. Rugelach freezes well and thaws quickly, which means it is well worth keeping on hand. But be warned: it is best to hide them in the back of the freezer, lest they disappear.